class User:
    def __init__(self,first_name,last_name):
        self.first_name = first_name
        self.last_name = last_name

    def describe_user(self):
        print(f'fist_name:{self.first_name} , last_name:{self.last_name}')

    def greet_user(self):
        print(f'Hello! Good to see you , {self.first_name}{self.last_name}!')